Today, human beings obtains most of the energy from oil, coal, nuclear power, natural gas, etc., but these fossil energy source and nuclear energy source are expected to be exhausted in the near future. Therefore, countries around the world have accelerated the research and development of renewable energy. Particularly, the sunlight power generation has drawn much attention, since electric power can be obtained from any sunlit place and does not generate pollution, unlike other electricity generation methods.
For sunlight power generation, a semiconductor device that converts solar energy into electrical energy is needed. Such a semiconductor device is referred to as a solar cell. In general, since a maximum voltage that can be generated by only one unit solar cell is about 0.5 V, unit solar cells interconnected in series should be used. A module in which unit solar cells are modularized by interconnecting them is referred to as a solar cell module.
Manufacturing processes for a solar cell module may be divided into a cell test process, a tabbing process, a lay-up process, a lamination process, and a module test process.
In a first process, i.e., the cell test process, solar cells having various electrical properties are tested and classified into several groups having a similar electrical property. In a second process, i.e., the tabbing process, several solar cells are connected in series by means of conductive ribbons. In a third process, i.e., the lay-up process, the solar cells that are connected in a line are arranged in a desired shape, and then low-iron reinforced glass, ethylene-vinyl acetate copolymer (EVA), a back sheet, etc. are stacked on them. In a fourth process, i.e., the lamination process, a resultant structure which is obtained in the form of a solar cell module by performing the lay-up process is processed to have durability and waterproofness by vacuum-compressing it at a high temperature. Finally, in the module test process, the finished solar cell module is tested to check whether it operates normally or not.
In this regard, the tabbing process in which several solar cells are connected by means of conductive ribbons is a key process among the manufacturing processes for a solar cell module. If the conductive ribbons are not appropriately bonded to the cells, the performance and quality of the whole solar cell module are deteriorated. The tabbing process is briefly described below. First, a plurality of conductive ribbons supplied from a reel are cut. Then, the conductive ribbons and solar cells are exposed to a high-temperature atmosphere while repeating that one sides of conductive ribbons are placed on a solar cell to lie on the cell and another solar cell is placed and stacked on the opposite sides of the conductive ribbons. The conductive ribbons are soldered to the cells under the high-temperature atmosphere, and thus, the plurality of cells are electrically connected by the conductive ribbons.
The background technology related to the present disclosure is disclosed in Korean registered patent publication No. 10-1058399.